GHSA-8QWJ-4JXW-M8JW

Vulnerability from github – Published: 2026-03-23 06:30 – Updated: 2026-03-30 19:30
VLAI?
Summary
jsrsasign: Negative Exponent Handling Leads to Signature Verification Bypass
Details

Versions of the package jsrsasign before 11.1.1 are vulnerable to Incorrect Conversion between Numeric Types due to handling negative exponents in ext/jsbn2.js. An attacker can force the computation of incorrect modular inverses and break signature verification by calling modPow with a negative exponent.

Severity ?
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
7.7 (High)
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:P
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{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "jsrsasign"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "11.1.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-4602"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-681"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-03-30T19:30:01Z",
    "nvd_published_at": "2026-03-23T06:16:22Z",
    "severity": "HIGH"
  },
  "details": "Versions of the package jsrsasign before 11.1.1 are vulnerable to Incorrect Conversion between Numeric Types due to handling negative exponents in ext/jsbn2.js. An attacker can force the computation of incorrect modular inverses and break signature verification by calling modPow with a negative exponent.",
  "id": "GHSA-8qwj-4jxw-m8jw",
  "modified": "2026-03-30T19:30:01Z",
  "published": "2026-03-23T06:30:29Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-4602"
    },
    {
      "type": "WEB",
      "url": "https://github.com/kjur/jsrsasign/pull/650"
    },
    {
      "type": "WEB",
      "url": "https://github.com/kjur/jsrsasign/commit/5ea1c32bb2aa894b4bd29849839afe4f98728195"
    },
    {
      "type": "WEB",
      "url": "https://gist.github.com/Kr0emer/7ecd2be7d17419e4677315ef3758faf5"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/kjur/jsrsasign"
    },
    {
      "type": "WEB",
      "url": "https://security.snyk.io/vuln/SNYK-JS-JSRSASIGN-15371175"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:P",
      "type": "CVSS_V4"
    }
  ],
  "summary": "jsrsasign: Negative Exponent Handling Leads to Signature Verification Bypass"
}


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